[20p-P16-1~12] 15.3 III-V-group epitaxial crystals

[20p-P16-5] Optical anisotropy of GaSb type-II nanorods on vicinal (111)B GaAs

〇Takuya Kawazu¹, Takeshi Noda¹, Yoshiki Sakuma¹, Hiroyuki Sakaki^1,2 (1.NIMS, 2.Toyota Tech. Inst.)

Keywords:semiconductor

Self-assembled GaSb type-II nanorods were formed on a vicinal (111)B GaAs substrate by molecular beam epitaxy. We studied their optical anisotropy and found that the GaSb nanorods are elongated and aligned along the [1 0 1] direction, where the average length, width, and height are about 84, 30, and 2.5 nm. Polarized photoluminescence (PL) measurements showed that the peak of the GaSb nanorods is observed at about 1.1 eV, where the PL intensity is largest for the [1 0 1] polarization and smallest for the polarization perpendicular to it. The polarization degree is more than 20% and depends on the recombination energy. By comparing with a theoretical model based on 4x4 Luttinger-Kohn Hamiltonian, we found that the experimental results are explained by considering the Sb/As inter-diffusion and the nanorod height distribution.